I am getting only 250khash with 2x 7950 vapor-x
ALTMiner --scrypt -o
http://127.0.0.1:32768 -u user -p pass -w 256 -I 12 -g 2 --gpu-memclock 1500 --gpu-engine 1000 --gpu-powertune -20 --thread-concurrency 4164 --auto-fan --queue 0 --temp-target 70 --temp-overheat 85 --gpu-fan 60-95
try the link i gave above and find setting for your card. for me, -I 13 is the best, and lower clock n memclock giving almost same result. here is my config for 270x :
--gpu-engine 1080 --gpu-memclock 1210 --auto-fan --temp-target 80,75 --temp-overheat 90 --temp-cutoff 95 --gpu-powertune -20 --worksize 256 -I 13 --lookup-gap 0
Thanks. Strangely I had better hashrate with vertcoin.
And I have found my first solo block 33 ALT! Yay.